Figure 1
AP and lateral knee X-ray
Cyclops lesion in absence of anterior ligament reconstruction
SectionMusculoskeletal system
Case TypeClinical Cases
AuthorsLuis Gijón de la Santa, Irene Méndez Mesón, José Antonio Pérez Retortillo
Connected authors
43 years, female
Clinical History
A 46-year-old woman presented with history of trauma seven months before.
Since then she had lost full extension; pain and an audible clunk with terminal extension.
Clinically the knee was stable and no meniscal tear was suspected.
X-ray and MRI were performed.
She has no history of arthroscopic knee surgery.
Since then she had lost full extension; pain and an audible clunk with terminal extension.
Clinically the knee was stable and no meniscal tear was suspected.
X-ray and MRI were performed.
She has no history of arthroscopic knee surgery.
Imaging Findings
X-ray study was normal (Fig. 1).
MRI showed a 15 mm soft tissue nodule in the intercodylar notch near the tibial insertion of the anterior cruciate ligament (ACL). This lesion is isointense to muscle in PD, T1- and T2-weighted images (Fig. 2-4). No cruciate ligaments torn or meniscal tears were observed.
MRI showed a 15 mm soft tissue nodule in the intercodylar notch near the tibial insertion of the anterior cruciate ligament (ACL). This lesion is isointense to muscle in PD, T1- and T2-weighted images (Fig. 2-4). No cruciate ligaments torn or meniscal tears were observed.
Discussion
The cyclops lesion is a fibrous nodule in the intercondylar notch near the tibial insertion of ACL. It was first described in patients with ACL reconstruction [1] but recently it has been reported cases without this antecedent [2].
The exact aetiology is uncertain.
In patients with ACL reconstructions has been linked to a result of a fibroproliferative process after surgery (because of debris, residual tissue or broken graft fibers).
In patients without knee surgery it has been related with a history of trauma. Several authors have supposed that this lesion occurs as a result of microtrauma of subclinically torn ACL fibers even when there is clinically or radiologically intact ACL [1].
MRI shows a rounded mass with a similar signal intensity to the muscle in the intercondylar notch adjacent to the ACL [3].
Cyclops lesion when symptomatic is named cyclops syndrome. The symptoms are pain, loss full extension and a palpable and audible clunk with extension [4, 5].
Treatment is arthroscopic excision when symptomatic [6].
The soft tissue nodule is named cyclops lesion lesion because of its arthroscopic appearance like a rounded mass with vessels which resemble the eye of the cyclops of Greek mythology [5].
The exact aetiology is uncertain.
In patients with ACL reconstructions has been linked to a result of a fibroproliferative process after surgery (because of debris, residual tissue or broken graft fibers).
In patients without knee surgery it has been related with a history of trauma. Several authors have supposed that this lesion occurs as a result of microtrauma of subclinically torn ACL fibers even when there is clinically or radiologically intact ACL [1].
MRI shows a rounded mass with a similar signal intensity to the muscle in the intercondylar notch adjacent to the ACL [3].
Cyclops lesion when symptomatic is named cyclops syndrome. The symptoms are pain, loss full extension and a palpable and audible clunk with extension [4, 5].
Treatment is arthroscopic excision when symptomatic [6].
The soft tissue nodule is named cyclops lesion lesion because of its arthroscopic appearance like a rounded mass with vessels which resemble the eye of the cyclops of Greek mythology [5].
Differential Diagnosis List
Cyclops lesion in absence of anterior ligament reconstruction
Nodular synovitis (focal pigmented villonodular synovitis)
Cyclopoid scar
Final Diagnosis
Cyclops lesion in absence of anterior ligament reconstruction
References
[1] Dhanda S, Sanghvi D, Pardiwala D. (2010) Case Series: Cyclops lesion - extension loss after ACL reconstruction. Indian J Radiol Imaging Aug;20(3):208-10. (PMID: 21042447)
[2] Runyan BR, Bancroft LW, Peterson JJ, Kransdorf MJ, Berquist TH, Ortiguera CJ. (2007) Cyclops lesions that occur in the absence of prior anterior ligament reconstruction. Radiographics Nov-Dec;27(6):e26. (PMID: 17712103)
[3] Recht MP, Piraino DW, Cohen MA, Parker RD, Bergfeld JA. (1995) Localized anterior arthrofibrosis (cyclops lesion) after reconstruction of the anterior cruciate ligament: MR imaging findings. AJR Am J Roentgenol Aug;165(2):383-5. (PMID: 7618562)
[4] Wang J, Ao Y. (2009) Analysis of different kinds of cyclops lesions with or without extension loss. Arthroscopy Jun;25(6):626-31. (PMID: 19501293)
[5] Jackson DW, Schaefer RK. (1990) Cyclops syndrome: loss of extension following intra-articular anterior cruciate ligament reconstruction. Arthroscopy 6(3):171-8. (PMID: 2206179)
[6] W. Norman Scott. (2012) Insall & Scott Surgery of the Knee. 5th edition.
Case information
| URL: | https://www.eurorad.org/case/10235 |
| DOI: | 10.1594/EURORAD/CASE.10235 |
| ISSN: | 1563-4086 |
Figure 3
Sagittal PD FSE with fat sat.
Sagittal PD FSE with fat sat.
A. Shows a rounded mass isointense to muscle. Note the integrity of ACL.
B. Shows the integrity of PCL ( posterior cruciate ligament)
Sagittal PD FSE with fat sat.
A. Shows a rounded mass isointense to muscle. Note the integrity of ACL.
B. Shows the integrity of PCL ( posterior cruciate ligament).
AP and lateral knee X-ray
Sagittal T1
Sagittal T1 shows a nodular soft tissue mass in the intercondylar notch near the ACL insertion. This lesion is isointense to muscle.
Gijón L. , Department of Radiology, Hospital Universitario de Guadalajara, Guadalajara, Spain.
Gijón L. , Department of Radiology, Hospital Universitario de Guadalajara, Guadalajara, Spain.
Sagittal T1 shows a nodular soft tissue mass in the intercondylar notch near the ACL insertion. This lesion is isointense to muscle.
Gijón L. , Department of Radiology, Hospital Universitario de Guadalajara, Guadalajara, Spain.
Gijón L. , Department of Radiology, Hospital Universitario de Guadalajara, Guadalajara, Spain.
Sagittal PD FSE with fat sat.
Sagittal PD FSE with fat sat.
A. Shows a rounded mass isointense to muscle. Note the integrity of ACL.
B. Shows the integrity of PCL ( posterior cruciate ligament)
Gijón L. , Department of Radiology, Hospital Universitario de Guadalajara, Guadalajara, Spain.
Gijón L. , Department of Radiology, Hospital Universitario de Guadalajara, Guadalajara, Spain.
Sagittal PD FSE with fat sat.
A. Shows a rounded mass isointense to muscle. Note the integrity of ACL.
B. Shows the integrity of PCL ( posterior cruciate ligament).
Gijón L. , Department of Radiology, Hospital Universitario de Guadalajara, Guadalajara, Spain.
Gijón L. , Department of Radiology, Hospital Universitario de Guadalajara, Guadalajara, Spain.
Axial T2 with fat sat
Axial T2 with fat sat shows a hypointense lesion in the intercondilar notch (orange circle).
Gijón L, Department of Radiology, Hospital Universitario de Guadalajara, Guadalajara, Spain.
Gijón L, Department of Radiology, Hospital Universitario de Guadalajara, Guadalajara, Spain.
Axial T2 with fat sat shows a hypointense lesion in the intercondilar notch (orange circle).
Gijón L, Department of Radiology, Hospital Universitario de Guadalajara, Guadalajara, Spain.
Gijón L, Department of Radiology, Hospital Universitario de Guadalajara, Guadalajara, Spain.